From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from lb2-smtp-cloud2.xs4all.net ([194.109.24.25]:58309 "EHLO lb2-smtp-cloud2.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbbGIMNd (ORCPT ); Thu, 9 Jul 2015 08:13:33 -0400 Message-ID: <559E6538.9080100@xs4all.nl> Date: Thu, 09 Jul 2015 14:12:40 +0200 From: Hans Verkuil MIME-Version: 1.0 To: Jan Kara CC: linux-media@vger.kernel.org, Mauro Carvalho Chehab , linux-samsung-soc@vger.kernel.org, linux-mm@kvack.org, Andrew Morton Subject: Re: [PATCH 0/10 v6] Helper to abstract vma handling in media layer References: <1434636520-25116-1-git-send-email-jack@suse.cz> <20150709114848.GA9189@quack.suse.cz> In-Reply-To: <20150709114848.GA9189@quack.suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 07/09/2015 01:48 PM, Jan Kara wrote: > Hello, > > Hans, did you have a chance to look at these patches? I have tested them > with the vivid driver but it would be good if you could run them through > your standard testing procedure as well. Andrew has updated the patches in > his tree but some ack from you would be welcome... I've planned a 'patch day' for Monday. So hopefully you'll see a pull request by then. Regards, Hans > > Honza > On Thu 18-06-15 16:08:30, Jan Kara wrote: >> Hello, >> >> I'm sending the sixth version of my patch series to abstract vma handling from >> the various media drivers. Since the previous version I have added a patch to >> move mm helpers into a separate file and behind a config option. I also >> changed patch pushing mmap_sem down in videobuf2 core to avoid lockdep warning >> and NULL dereference Hans found in his testing. I've also included small >> fixups Andrew was carrying. >> >> After this patch set drivers have to know much less details about vmas, their >> types, and locking. Also quite some code is removed from them. As a bonus >> drivers get automatically VM_FAULT_RETRY handling. The primary motivation for >> this series is to remove knowledge about mmap_sem locking from as many places a >> possible so that we can change it with reasonable effort. >> >> The core of the series is the new helper get_vaddr_frames() which is given a >> virtual address and it fills in PFNs / struct page pointers (depending on VMA >> type) into the provided array. If PFNs correspond to normal pages it also grabs >> references to these pages. The difference from get_user_pages() is that this >> function can also deal with pfnmap, and io mappings which is what the media >> drivers need. >> >> I have tested the patches with vivid driver so at least vb2 code got some >> exposure. Conversion of other drivers was just compile-tested (for x86 so e.g. >> exynos driver which is only for Samsung platform is completely untested). >> >> Andrew, can you please update the patches in mm three? Thanks! >> >> Honza >> >> Changes since v5: >> * Moved mm helper into a separate file and behind a config option >> * Changed the first patch pushing mmap_sem down in videobuf2 core to avoid >> possible deadlock >> >> Changes since v4: >> * Minor cleanups and fixes pointed out by Mel and Vlasta >> * Added Acked-by tags >> >> Changes since v3: >> * Added include into mm/gup.c as it's needed for some archs >> * Fixed error path for exynos driver >> >> Changes since v2: >> * Renamed functions and structures as Mel suggested >> * Other minor changes suggested by Mel >> * Rebased on top of 4.1-rc2 >> * Changed functions to get pointer to array of pages / pfns to perform >> conversion if necessary. This fixes possible issue in the omap I may have >> introduced in v2 and generally makes the API less errorprone.